Which functional element is removed in Cloud RAN compared to traditional RAN?

In the context of Cloud RAN, the Baseband Units (BBUs) are centralized and virtualized as part of the architecture shift away from traditional RAN setups. In traditional RAN, BBUs are typically located close to the radio equipment at each cell site, where they handle the processing associated with wireless communication.

By centralizing the BBUs in Cloud RAN, the need for individual, physical BBUs at each cell site is eliminated. This centralization allows for greater efficiency, as it leverages cloud technologies to optimize processing and resource allocation across multiple sites. This architecture not only reduces hardware costs at the cell sites but also enhances flexibility and scalability, enabling operators to more quickly adapt to changing network demands.

This transition reflects a significant change in how RAN is designed, and highlights the shift towards more software-driven, cloud-based solutions, contrasting sharply with the traditional hardware-centric models. The other options provided do not capture this transformative functional element of Cloud RAN architecture accurately.